I am Receiving Error Message

Hello can anyone help me I am receiving this error message
Windows\system32\config\system corrupt or not detected
I am Running windows xp Media service pack3
I have two hrd disks and my primary does not run at start up but bios does recognize it
I have to boot my other hrd disk and then open hard disk from my computer and I can see the hrd disk and its files but like i said it wont boot from start up. can anyone help me out?